Endoscopic surgical clip applier

ABSTRACT

An endoscopic surgical clip applier includes a handle assembly having a trigger, an endoscopic assembly, a pair of jaw members, a drive bar disposed within the housing of the handle assembly, and a ratchet assembly disposed within the housing of the handle assembly. The drive bar is operatively coupled to the trigger and the pair of jaw members. The ratchet assembly includes a rack disposed on the drive bar, the rack defining a plurality of rack teeth, and a pawl housing slidably mounted within the housing of the handle assembly, the pawl housing having a pawl being selectively engageable with the plurality of rack teeth of the rack, wherein in a first position of the pawl housing, reversal of a direction of movement of the trigger is prohibited, and wherein in a second position of the pawl housing, reversal of the direction of movement of the trigger is permitted.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of and priority to U.S. Provisional Patent Application No. 62/453,551 filed Feb. 2, 2017, the entire disclosure of which is incorporated by reference herein.

BACKGROUND Technical Field

The present disclosure relates generally to surgical clip appliers. More particularly, the present disclosure relates to endoscopic surgical clip appliers having a release switch for a ratchet assembly thereof.

Description of Related Art

Endoscopic surgical staplers and surgical clip appliers are known in the art and are used for a number of distinct and useful surgical procedures. Minimally invasive procedures are often generally referred to as endoscopic procedures. Typically, a tube or cannula device is extended into the patient's body through the entrance incision to provide an access port. The port allows the surgeon to insert a number of different surgical instruments therethrough using a trocar and for performing surgical procedures far removed from the incision.

Endoscopic surgical clip appliers having various sizes that are configured to apply a variety of diverse surgical clips are known in the art and are capable of applying a single or multiple surgical clips during an entry to the body cavity. Such surgical clips are typically fabricated from a biocompatible material and are usually compressed over a vessel. Once applied to the vessel, the compressed surgical clip terminates the flow of fluid therethrough.

Endoscopic surgical clip appliers that are able to apply multiple clips in endoscopic or laparoscopic procedures during a single entry into the body cavity are described in commonly-assigned U.S. Pat. Nos. 5,084,057 and 5,100,420 to Green et al., which are both incorporated by reference in their entirety. Another multiple endoscopic surgical clip applier is disclosed in commonly-assigned U.S. Pat. No. 5,607,436 by Pratt et al., the contents of which is also hereby incorporated by reference herein in its entirety. These devices are typically, though not necessarily, used during a single surgical procedure.

U.S. Pat. No. 5,695,502 to Pier et al., the disclosure of which is hereby incorporated by reference herein, discloses a resterilizable endoscopic surgical clip applier. The endoscopic surgical clip applier advances and forms multiple clips during a single insertion into the body cavity. This resterilizable endoscopic surgical clip applier is configured to receive and cooperate with an interchangeable clip magazine so as to advance and form multiple clips during a single entry into a body cavity.

During endoscopic procedures it may be desirable and/or necessary to partially form clips, as is necessary, for example, to secure a catheter around tissue during a cholangiogram or other medical procedures.

Accordingly, a need exists for endoscopic surgical clip appliers that include a release switch for the ratchet assembly. As such, during a clip formation procedure, the clinician can actuate the release switch to reset the ratchet assembly and thus, only partially form a surgical clip.

SUMMARY

The present disclosure relates to endoscopic surgical clip appliers.

According to an aspect of the present disclosure, an endoscopic surgical clip applier is provided. The surgical clip applier includes a handle assembly, an endoscopic assembly, a drive bar, and a ratchet assembly. The handle assembly includes a housing, a fixed handle extending from the housing, and a trigger pivotally connected to the fixed handle. The endoscopic assembly is selectively connectable to the housing of the handle assembly and includes a shaft assembly and a pair of jaw members operatively coupled to, and extending from the shaft assembly. The drive bar is disposed within the housing of the handle assembly and is operatively coupled to the trigger and the pair of jaw members to move the pair of jaw members between a spaced apart configuration and an approximated configuration upon actuation of the trigger. The ratchet assembly is disposed within the housing of the handle assembly and includes a rack disposed on the drive bar, the rack defining a plurality of rack teeth and having a proximal end and a distal end, and a pawl housing slidably mounted within the housing of the handle assembly, the pawl housing having a pawl being selectively engageable with the plurality of rack teeth of the rack, wherein in a first position of the pawl housing, the pawl is in registration with the plurality of rack teeth of the rack to prohibit reversal of a direction of movement of the trigger until the pawl is disposed beyond the proximal end or the distal end of the rack and wherein in a second position of the pawl housing, the pawl is out of registration with the plurality of rack teeth of the rack to permit reversal of the direction of movement of the trigger after an initial engagement of the pawl with the rack.

In one embodiment, the ratchet assembly includes a release switch at least partially supported within the housing of the handle assembly and operatively associated with the pawl housing. The release switch is selectively actuatable to move the pawl housing from the first position thereof to the second portion thereof, wherein in the second position of the pawl housing, the pawl housing is moved laterally relative to the rack to disengage the pawl from the plurality of rack teeth of the rack.

In one aspect, the pawl housing defines a channel therein, wherein the pawl is located within the channel of the pawl housing.

In embodiments, the ratchet assembly includes a switch pin, wherein the pawl housing defines a central slot therein configured to locate the switch pin, the switch pin slidably extending through the channel of the pawl housing and the pawl to support the pawl within the channel of the pawl housing.

In some embodiments, the release switch includes a first end cap and a second end cap, wherein a first side of the housing includes a first switch slot configured to slidably receive the first end cap of the release switch and a second side of the housing includes a second switch slot configured to slidably receive the second end cap of the release switch.

In one embodiment, the first end cap of the release switch is supported on a first end of the switch pin, on a first side of the pawl housing, and the second end cap of the release switch is supported on a second end of the switch pin, on a second, opposite side of the pawl housing, such that the release switch is accessible via the first and second end caps from the first and second sides of the pawl housing, respectively, to actuate the release switch.

In one aspect, the release switch includes a first biasing member supported on the first end cap and extending between an internal wall of the first switch slot and the first side of the pawl housing, and a second biasing member supported on the second end cap and extending between an internal wall of the second switch slot and the second side of the pawl housing.

In embodiments, the first biasing member includes a first biasing force and the second biasing member includes a second biasing force, the first and second biasing forces configured to cooperate to maintain the pawl housing in the first position such that the pawl housing is centered relative to the rack and the pawl is in registration with the plurality of rack teeth.

In some embodiments, when the release switch is actuated, by actuating the first end cap thereof, the first end cap is moved towards the first side of the pawl housing such that the first end cap engages the pawl housing to move the pawl housing to the second position thereof, towards the second biasing member, and laterally relative to the rack to move the pawl out of registration with the plurality of rack teeth.

In one embodiment, when the release switch is actuated, by actuating the second end cap thereof, the second end cap is moved towards the second side of the pawl housing such that the second cap engages the pawl housing to move the pawl housing to the second position thereof, towards the first biasing member, and laterally relative to the rack to move the pawl out of registration with the plurality of rack teeth.

In one aspect, the rack includes a distal clearance and a proximal clearance configured to receive the pawl in an initial and/or a reset position.

In embodiments, the ratchet assembly includes a pawl spring configured to bias the pawl into registration with the rack in the first position, wherein in the second position, the pawl spring and at least one of the first biasing member and the second biasing member are configured to urge the pawl against a side of the rack until the pawl is located within the distal clearance or the proximal clearance of the rack.

In some embodiments, when the pawl is located within the distal clearance or the proximal clearance of the rack, at least one of the first biasing member and the second biasing member are configured to urge the pawl laterally to the first position thereof, wherein the pawl is centered relative to the rack such that the pawl is in registration with the plurality of rack teeth.

In one embodiment, the ratchet assembly includes a distal support pin and a proximal support pin, wherein an outer surface of the pawl housing further defines a distal support slot configured for locating the distal support pin and a proximal support slot configured for locating the proximal support pin, the distal support pin and the proximal support pin each coupled to the housing of the handle assembly to slidably mount the pawl housing within the housing of the handle assembly.

In one aspect, the endoscopic assembly further comprises a plurality of surgical clips slidably disposed within the shaft assembly and selectively formable between the pair of jaw members, wherein when the pawl housing is in the first position, the pawl is in registration with the rack disposed on the drive bar such that upon actuation of the trigger, the trigger is prevented from reversing the direction of movement thereof until the trigger is fully actuated and a distal most surgical clip of the plurality of surgical clips is fully formed between the pair of jaw members.

In embodiments, when the pawl housing is in the second position, the pawl is out of registration with the rack disposed on the drive bar such that upon partial actuation of the trigger, the trigger is capable of reversing the direction of movement thereof such that the distal most surgical clip of the plurality of surgical clips is partially formed between the pair of jaw members.

In some embodiments, the ratchet assembly includes a cover plate provided on the rack, the cover plate having a pair of wings extending along at least a portion of the rack to prevent lateral movement of the pawl housing and disengagement of the pawl from the plurality of rack teeth during a specific portion of the stroke length of the trigger.

According to another aspect of the present disclosure, an endoscopic surgical clip applier is provided. The surgical clip applier includes a handle assembly, a shaft assembly extending from the handle assembly, a pair of jaw members operatively coupled to, and extending from the shaft assembly, a drive bar, and a ratchet assembly. The handle assembly includes a fixed handle and a trigger pivotally connected to the fixed handle. The drive bar is disposed within the handle assembly and is operatively coupled to the trigger and the pair of jaws members to move the pair of jaw members between a spaced apart configuration and an approximated configuration upon actuation of the trigger. The ratchet assembly is disposed within the handle assembly and includes a rack and a pawl housing. The rack is defined on a top portion of the drive bar, the rack including a plurality of rack teeth and having a proximal end and a distal end. The pawl housing is movably mounted within the handle assembly, the pawl housing having a pawl being selectively engageable with the plurality of rack teeth of the rack to prohibit, upon actuation of the trigger, a reversal of a direction of movement of the trigger until the pawl is disposed beyond the proximal end or the distal end of the rack after an initial engagement of the pawl with the rack.

BRIEF DESCRIPTION OF THE DRAWINGS

A particular embodiment of an endoscopic surgical clip applier is disclosed herein with reference to the drawings wherein:

FIG. 1 is a perspective view of an endoscopic surgical clip applier, according to the present disclosure including an endoscopic assembly and a handle assembly;

FIG. 2A is a perspective view, with parts separated, of the handle assembly of FIG. 1;

FIG. 2B is an enlarged perspective view of the indicated area of detail of FIG. 2A, illustrating a pawl housing and a pawl of the handle assembly of FIG. 1;

FIG. 3 is a perspective view of the handle assembly of FIG. 1 with at least a housing half-section removed therefrom;

FIG. 4A is a perspective view, of the handle assembly of FIG. 1 with at least a top housing portion removed or cut away therefrom, illustrating a ratchet assembly thereof;

FIG. 4B is an enlarged perspective view of the indicated area of detail of FIG. 4A, illustrating the ratchet assembly;

FIG. 5 is an enlarged perspective view illustrating the pawl housing including the pawl of the ratchet assembly of the handle assembly of FIG. 1;

FIG. 6 is a cross-sectional, plan view, as taken through 6-6 of FIG. 1, illustrating the ratchet assembly in a first position;

FIG. 7 is a cross-sectional, perspective view illustrating the ratchet assembly in the first position of FIG. 6;

FIG. 8 is a cross-sectional, perspective view illustrating the ratchet assembly in a second position;

FIG. 9 is a cross-sectional, plan view, as taken through 6-6 of FIG. 1, illustrating the ratchet assembly in the second position;

FIG. 10 is a cross-sectional, perspective view of the handle assembly of FIG. 1 with at least a housing half-section removed therefrom, illustrating the ratchet assembly in the second position and the pawl out of registration with a rack of the ratchet assembly;

FIG. 11 is a cross-sectional, perspective view of the handle assembly of FIG. 1 with at least a housing half-section removed therefrom, illustrating the ratchet assembly resetting to the first position and the pawl centered relative to the rack of the ratchet assembly;

FIG. 12 is perspective view of the rack of the ratchet assembly, according to an alternative embodiment of the present disclosure;

FIG. 13 is perspective view of the rack of the ratchet assembly, according to a further alternative embodiment of the present disclosure; and

FIG. 14 is a perspective view of the endoscopic assembly, with parts separated.

DETAILED DESCRIPTION OF EMBODIMENTS

In accordance with the present disclosure, an endoscopic surgical clip applier includes a ratchet assembly having a rack, a pawl, and a release switch. In one embodiment, upon actuation of a trigger, the pawl is configured to engage a plurality of rack teeth of the rack to prohibit release and reversal of a direction of movement of the trigger until the pawl is disposed beyond a proximal end or a distal end of the rack. In one aspect, the release switch is selectively actuatable to move the pawl out of registration with the plurality of rack teeth of the rack such that the direction of movement of the trigger may be reversed. It is contemplated that the release switch may be useful to partially form clips, as is necessary, for example, to secure a catheter around tissue during a cholangiogram or other medical procedures.

Embodiments of endoscopic surgical clip appliers, in accordance with the present disclosure, will now be described in detail with reference to the drawing figures wherein like reference numerals identify similar or identical structural elements. As shown in the drawings and described throughout the following description, as is traditional when referring to relative positioning on a surgical instrument, the term “proximal” refers to the end of the apparatus which is closer to the user and the term “distal” refers to the end of the apparatus which is further away from the user.

Referring now to FIGS. 1-14, an endoscopic surgical clip applier in accordance with an embodiment of the present disclosure, and assembly in a particular configuration, is generally designated as 10. Surgical clip applier 10 generally includes a handle assembly 100 and an endoscopic assembly 200 that extends distally from handle assembly 100. Generally, endoscopic assembly 200 includes a hub assembly 210, a shaft assembly 220 extending from hub assembly 210, and a pair of jaws 250 pivotally connected to a distal end of shaft assembly 220. Optionally, at least one disposable surgical clip cartridge assembly (not shown) may be selectively loadable into shaft assembly 220 of endoscopic assembly 200.

Referring now to FIGS. 1-2B, handle assembly 100 of surgical clip applier 10 is shown and will be described. Handle assembly 100 includes a housing 102 having a first or right side half-section 102 a and a second or left side half-section 102 b. Housing 102 of handle assembly 100 further includes or defines a nose 102 c for supporting hub assembly 210 of endoscopic assembly 200, and a fixed handle 102 d.

Housing 102 of handle assembly 100 may be formed of a suitable plastic or thermoplastic material. It is further contemplated that housing 102 of handle assembly 100 may be fabricated from stainless steel or the like.

Handle assembly 100 includes a trigger 104 pivotably supported between right side half-section 102 a and left side half-section 102 b of housing 102. Trigger 104 is pivotably movable in a first direction such that the trigger 104 and the fixed handle 102 d are approximated and pivotably movable in a second, opposite, direction such that the trigger 104 and the fixed handle 102 d are spaced-apart.

A drive bar 106 is supported within the housing 102 of the handle assembly 100. The drive bar 106 is operatively coupled to the trigger 104 and the pair of jaws 250 to move the pair of jaws between a spaced-apart configuration and an approximated configuration upon actuation of the trigger 104. Specifically, the handle assembly 100 includes a wishbone link 108 configured to couple the trigger 104 and the drive bar 106. Wishbone link 108 includes a first end having a tail 108 a and a second end having a first arm and a second arm 108 b, 108 c spaced-apart to define a space 108 d therebetween. The tail 108 a of the wishbone link 108 is pivotably connected to the trigger 104 through a trigger slot 104 a. Specifically, tail 108 a of wishbone link 108 includes an opening 108 f configured for pivotably locating a pin 104 b defined within trigger slot 104 a. The space 108 d between the first and second arms 108 b, 108 c is configured to receive the drive bar 106. The first and second arms 108 b, 108 c of wishbone link 108, and the drive bar 106 includes corresponding apertures 108 e, 106 c, respectively, configured to locate a drive bar pin 110 to pivotably connect the wishbone link 108 and the drive bar 106. The wishbone link 108 is configured to translate the pivotal movement of the trigger 104 into longitudinal movement of the drive bar 106, as will be detailed below.

In one embodiment, the drive bar 106 is a substantially flat member having a distal end portion 106 a and a proximal end 106 b. Generally, distal end portion 106 a of drive bar 106 includes an hook member 114 that is provided to mate with a feature of endoscopic assembly 200. As such, drive bar 106 is configured to move one or more driving structures to load, and actuate the pair of jaws 250 to form a fully formed or partially formed clip, and then reset to an initial position for the next clip application. A biasing member, such as, for example, a return spring 112 is disposed to surround the drive bar 106 adjacent the distal end portion 106 a. After the trigger 104 is actuated and the wishbone link 108 advances the drive bar 106 in a longitudinal or distal manner, the return spring 112 is provided to return the drive bar 106 and the trigger 104 to its original position for the next clip application.

With additional reference to FIGS. 3-5, surgical clip applier 10 includes a ratchet assembly 300 disposed within housing 102 of handle assembly 100. The ratchet assembly 300 includes a rack 310, a pawl housing 320 having a pawl 330 disposed therein, and a release switch 340 at least partially supported within housing 102 of handle assembly 100.

As shown in FIG. 3, the rack 310 is supported by or is provided on a top surface 106 d of the drive bar 106 and includes a distal portion 310 a and a proximal portion 310 b. The rack 310 defines a plurality of rack teeth 312 in series between the distal portion 310 a and the proximal portion 310 b. The rack 310 also includes a distal clearance or well 314 a located adjacent the distal end 310 a and a proximal clearance or well 314 b located adjacent the proximal end 310 b of the rack 310. The distal well 314 a and the proximal well 314 b are configured to receive the pawl 330 in an initial and/or reset position, as will be detailed further.

A shown in FIG. 4B, the pawl housing 320 is slidably mounted within the handle assembly 100 between the right side half-section 102 a and the left side half-section 102 b of the housing 102. Specifically, the ratchet assembly 300 includes a distal support pin 302 a and a proximal support pin 302 b and the pawl housing 320 includes a distal support slot 322 a and a proximal support slot 322 b configured to locate the distal support pin 302 a and the proximal support pin 302 b, respectively. The distal support pin 302 a and the proximal support pin 302 b are mounted onto a plurality of corresponding slots 103 a within the housing 102 to slidably mount the pawl housing 320 within the housing 102 of the handle assembly 100. In embodiments, as best illustrated in FIG. 5, pawl housing 320 further includes a first guide channel 323 a and a second guide channel 323 b configured for locating a first guide feature 103 b and a second guide feature 103 c, respectively, extending from at least one of the right side half-section 102 a or the left side half-section 102 b of housing 102. It is contemplated that the first and second guide features 103 b, 103 c are provided to align the distal and proximal support slots 322 a, 322 b of the pawl housing 320 with the plurality of corresponding slots 103 a of housing 102 for locating the distal and proximal support pins 302 a, 302 b, respectively.

As shown in FIGS. 2B and 5, the pawl housing 320 further defines a channel or recess 324 configured to locate the pawl 330 therein. Pawl 330 is pivotably connected to the pawl housing 320 by a switch pin 332 at a location wherein pawl 330 is in substantial operative engagement with the rack 310. The switch pin 332 extends through a central slot 326 defined in the pawl housing 320 and a corresponding slot 334 defined in the pawl 330. The ratchet assembly 300 further includes a pawl spring 336 disposed within the pawl housing 320 and configured to vertically bias pawl 330 into operative engagement with the rack 310. Specifically, the pawl spring 336 includes a distal hook 336 a configured to latch onto the distal support pin 302 a and a proximal hook 336 b configured to latch onto the proximal support pin 302 b. It is contemplated that pawl spring 336 is positioned in a manner configured to maintain a pawl tooth 338 of the pawl 330 in engagement with the plurality of rack teeth 312, as well as to maintain the pawl 330 in a rotated or canted position.

Referring now to FIG. 6, in a first position, the pawl 330 is engagable with the rack 310 to restrict longitudinal movement of rack 310 and, in turn, trigger 104. In use, as trigger 104 is actuated (from a fully un-actuated position), rack 310 is also moved into engagement with pawl 330. Rack 310 has a length which allows pawl 330 to reverse and advance back over rack 310, when rack 310 changes between proximal or distal movement (after pawl tooth 338 enters distal clearance 314 a), as trigger 104 reaches a fully actuated or fully un-actuated position. The relative lengths and sizes of rack 310 of ratchet assembly 300, trigger 104 and drive bar 106 define a stroke length of trigger 104, drive bar 106 or handle assembly 100.

Ratchet assembly 300 further includes release switch 340 at least partially supported within housing 102 of handle assembly 100. Release switch 340 is operatively associated with pawl housing 320 and is operable to selectively move pawl housing 320, and in turn pawl 330, into or out of registration with the plurality of rack teeth 312 of rack 310.

In this manner, when pawl 330 is moved to a second position, out of registration with the plurality of rack teeth 312 of rack 310 (see FIG. 9), trigger 104 is free to open and close as needed due to pawl 330 having no blocking effect on rack 310 of ratchet assembly 300. As such, trigger 104 may be partially actuated (without having to be fully actuated), and may be returnable to a fully un-actuated position. Such a feature permits a user to partially squeeze or actuate trigger 104 for performing a cholangiogram procedure or the like.

With reference to FIG. 6, release switch 340 includes a first end cap 342 a slidably supported on a first end portion 332 a of switch pin 332 and a second end cap 342 b slidably supported on a second end portion 332 b of switch pin 332.

First end cap 342 a has a first extension 343 a and defines a substantially “T” shaped profile. First end cap 342 a defines a first channel or bore 345 a therethrough, sized and configured to slidably receive the first end portion 332 a of switch pin 332. Similarly, second end cap 342 b has a second extension 343 b and defines a substantially “T” shaped profile. Second end cap 342 b defines a second channel or bore 345 b therethrough, sized and configured to slidably receive the second end portion 332 b of switch pin 332.

In one embodiment, first and second end caps 342 a, 342 b are cylindrically shaped, each including a first diameter “D1”. Similarly, in one embodiment, first and second extensions 343 a, 343 b are cylindrically shaped, each including a second diameter “D2” that is less than the first diameter “D1”. Alternatively, first and second end caps 342 a, 342 b and first and second extensions 343 a, 343 b, respectively, may include various shapes and sizes as necessary for its intended purpose.

Right side half-section 102 a of housing 102 includes a first switch slot or bore 105 sized and configured to slidably receive the first end cap 342 a and left side half-section 102 b of housing 102 includes a second switch slot or bore 107 sized and configured to slidably receive the second end cap 342 b. Once first and second end caps 342 a, 342 b are received within first and second switch slots 105, 107, respectively, first and second extensions 343 a, 343 b are provided to be in contact with a first side 328 a and a second side 328 b of pawl housing 320, respectively.

In one embodiment, first and second switch slots 105, 107 each include a first portion 105 a, 107 a, respectively, defining a third diameter “D3” that is slightly larger than the first diameters “D1” of first and second end caps 342 a, 342 b to enable slidable insertion of first and second end caps 342 a, 342 b into first portions 105 a, 107 a without significant play or clearance therebetween. First and second switch slots 105, 107 each further include an internal wall 105 b, 107 b. Internal walls 105 b, 107 b are provided to prevent slidable insertion of first and second end caps 342 a, 342 b beyond first portions 105 a, 107 a, respectively. Internal walls 105 b, 107 b each define an opening 105 c, 107 c, respectively, defining a fourth diameter “D4” that is less than the third diameter “D3” of first portions 105 a, 107 a. The fourth diameter “D4” of each opening 105 c, 107 c is slightly larger than the second diameters “D2” of the first and second extensions 343 a, 343 b to enable slidable insertion of the first and second extensions 343 a, 343 b into the openings 105 c, 107 c without significant play or clearance therebetween.

First and second end caps 342 a, 342 b project from first and second switch slots 105, 107, respectively, and may be actuated by a finger of a user to actuate release switch 340. It is contemplated that first portions 105 a, 107 a, of first and second switch slots 105, 107, respectively, provide sufficient runway to enable first and second end caps 342 a, 342 b, respectively, to move therethrough to actuate release switch 340.

In one embodiment, housing 102 of handle assembly 100 may be provided with guard walls (not specifically shown) surrounding the first and second end caps 342 a, 342 b in order to inhibit inadvertent actuation of release switch 340. In some embodiments, the first and second end caps 342 a, 342 b may be flush with an outer surface of housing 102 of handle assembly 100 in order to also inhibit inadvertent actuation of release switch 340.

Release switch 340 is movable, upon actuation of first or second end caps 342 a, 342 b, between the first position (noted above; see FIGS. 3, 6, and 7) in which ratchet assembly 300 is “on” or “activated” such that pawl 330 is in or moved into operative engagement/registration with the plurality of rack teeth 312, thereby enabling or re-enabling the operability of ratchet assembly 300, and the second position (noted above; see FIGS. 8-10) in which ratchet assembly 300 is “off” or “de-activated” such that pawl 330 is out of or moved out of operative engagement/registration with the plurality of rack teeth 312.

It is contemplated that release switch 340, and in turn ratchet assembly 300, default to the first position, in which pawl 330 is engaged with/in registration with the plurality of rack teeth 312. To that end, release switch 340 includes a first biasing member 344 supported on first extension 343 a of first end cap 343 a, extending between a first side 328 a of pawl housing 320 and internal wall 105 b of first switch slot 105, and includes a second biasing member 346 supported on second extension 343 b of second end cap 342 b, extending between a second side 328 b of pawl housing 320 and internal wall 107 b of second switch slot 107. The first biasing member 344 includes a first biasing force “BF1” and is provided to bias or urge second end cap 342 b away from internal wall 107 b of second switch slot 107. Similarly, the second biasing member 346 includes a second biasing force “BF2” and is provided to bias or urge first end cap 342 a away from internal wall 105 b of first switch slot 105. Together, first and second biasing members 344, 346 cooperate to maintain pawl housing 320 in the first position such that pawl housing 320 is centered relative to rack 310 (see FIG. 6) and the pawl 330 is engagable with the rack 310 to restrict longitudinal movement of rack 310.

As noted above, release switch 340 is actuatable from the first position towards the second position, upon actuation of the first or second end caps 342 a, 342 b. Accordingly, for illustrative purposes, the use of release switch 340 will be detailed with reference to actuation of the first end cap 342 a.

Referring now to FIGS. 6-11, in use, when release switch 340 is actuated towards the second position by moving or depressing first end cap 342 a laterally towards the first side 328 a of the pawl housing 320, first extension 343 a of first end cap 343 a engages first side 328 a of pawl housing 320 to move pawl housing 320 towards second biasing member 346 and pawl 330 out of operative engagement/registration with the plurality of rack teeth 312 of rack 310. The movement of pawl housing 320 towards second biasing member 346, compresses second biasing member 346 between second side 328 b of pawl housing 320 and internal wall 107 b of second switch slot 107.

As noted above, pawl housing 320 includes a pawl spring 336 disposed therein and configured to vertically bias pawl 330. In the first position, pawl spring 336 vertically biases pawl 330 into operative engagement with the rack 310. In the second position, when pawl 330 is moved out of operative engagement/registration with the plurality of rack teeth 312 and abuts a side of rack 310, the combined biases of pawl spring 336 and second biasing member 346 acts on pawl 330 such that pawl 330 is wedged or held against the side of rack 310 (see FIG. 9) and disengaged from plurality of rack teeth 312 until rack 310 is moved proximally (see FIG. 10) such that pawl 330 is located within distal well 314 a (see FIG. 11) or until rack 310 is moved distally such that pawl 330 is located within proximal well 314 b. When pawl 330 is located within distal well 314 a or proximal well 314 b, second biasing member 346 is permitted to expand (without being impeded by the side of rack 310) such that second biasing force “BF2” acts on pawl housing 320 to move pawl housing 320 laterally back towards the first position wherein pawl 330 is centered relative to rack 310 such that pawl 330 is engagable with the plurality of rack teeth 312 of rack 310 upon further longitudinal movement of rack 310, thereby enabling or re-enabling the operability of ratchet assembly 300.

With brief reference to FIGS. 12 and 13, in embodiments, rack 310 may include features to prevent actuation of release switch 340 towards the second position during a specific portion of the stroke length of trigger 104. These features may be advantageous to prevent an inadvertent return of trigger 104 once a clip has been fully formed or partially formed but has not been fired from surgical clip applier 10. These features may also be advantageous to prevent inadvertent double loading of a clip into the pair of jaws 250.

In one embodiment, as illustrated in FIG. 12, rack 310 may include a cover plate 350 disposed thereon. Cover plate 350 includes a channel 352 through which the plurality of rack teeth 312 of rack 310 are accessible when cover plate 350 is disposed on rack 310. Cover plate 350 includes a pair of wings or walls 354 a, 354 b extending from opposing sides of channel 352 and towards pawl housing 320. The pair of wings 354 a, 354 b extend along at least a portion of a length of rack 310 to prevent lateral movement of pawl housing 320 and disengagement of pawl 330 from the plurality of rack teeth 312 during a specific portion of the stroke length of trigger 104.

In one embodiment, as illustrated in FIG. 13, rack 310 may instead include a pair of plates 360 a, 360 b affixed to opposite sides of rack 310. The pair of plates 360 a, 360 b extends from the opposite sides of rack 310 and towards pawl housing 320 to define a pair of shoulders or walls 362 a, 362 b on opposing sides of the plurality of rack teeth 312. The pair of shoulders 362 a, 362 b extends along at least a portion of a length of rack 310 to prevent lateral movement of pawl housing 320 and disengagement of pawl 330 from the plurality of rack teeth 312 during a specific portion of the stroke length of trigger 104.

As noted above, and illustrated in FIG. 14, surgical clip applier 10 includes an endoscopic assembly 200 having hub assembly 210, shaft assembly 220, and the pair of jaws 250. Hub assembly 210 is rotatably mounted on nose 102 c (see FIG. 2A) of housing 102 of handle assembly 100 and is connected to a proximal end portion of shaft assembly 220 to provide a three hundred sixty degree rotation of the shaft assembly 220 and the pair of jaws 250 thereon relative to a longitudinal center axis of shaft assembly 220. Hub assembly 210 has a suitable configuration so as to be rotated simply using a clinician's finger.

Endoscopic assembly 200 includes a spindle link 260 for operatively connecting drive bar 106 to a driving mechanism 400 to move the pair of jaws 250 between the spaced-apart configuration and the approximated configuration upon actuation of trigger 104. Specifically, hook member 114 (see FIG. 3) of drive bar 106 is coupled to a first end 260 a of spindle link 260 and a spindle 270 of drive mechanism 400 is coupled to a second end 260 b of spindle link 260. In this manner, translation of drive bar 106 in a distal and proximal direction can thus advance and retract spindle 270, respectively.

Drive mechanism 400 further includes an elongated clip channel member 280 for retaining a number of surgical clips 290 shown in an aligned manner above the clip channel member 280. A clip follower 282 and a clip follower spring 284 are provided to urge the surgical clips 290 distally through the elongated clip channel member 280. A channel cover 286 is provided to overlay the elongated clip channel member 280 and retain and guide the clip follower 282 and clip follower spring 284 and the surgical clips 290 distally in the elongated clip channel member 280.

Drive mechanism 400 also has a feed bar 410 for feeding the surgical clips 290 between the pair of jaws 250. Drive mechanism 400 also includes a filler component 420 and a wedge plate 430.

For a more detailed description of the construction and operation of endoscopic assembly 200, reference may be made to U.S. Pat. No. 7,637,917, the entire content of which is incorporated herein by reference.

It should be understood that the foregoing description is only illustrative of the present disclosure. Various alternatives and modifications can be devised by those skilled in the art without departing from the disclosure. Accordingly, the present disclosure is intended to embrace all such alternatives, modifications and variances. The embodiments described with reference to the attached drawing figures are presented only to demonstrate certain examples of the disclosure. Other elements, steps, methods and techniques that are insubstantially different from those described above and/or in the appended claims are also intended to be within the scope of the disclosure. 

What is claimed is:
 1. An endoscopic surgical clip applier, comprising: a handle assembly including: a housing; a fixed handle extending from the housing; and a trigger pivotally connected to the fixed handle; an endoscopic assembly selectively connectable to the housing of the handle assembly, the endoscopic assembly including: a shaft assembly; and a pair of jaw members operatively coupled to, and extending from the shaft assembly; a drive bar disposed within the housing of the handle assembly and operatively coupled to the trigger and the pair of jaw members to move the pair of jaw members between a spaced apart configuration and an approximated configuration upon actuation of the trigger; a ratchet assembly disposed within the housing of the handle assembly, the ratchet assembly including: a rack disposed on the drive bar, the rack defining a plurality of rack teeth and having a proximal end and a distal end; and a pawl housing slidably mounted within the housing of the handle assembly, the pawl housing having a pawl being selectively engageable with the plurality of rack teeth of the rack, wherein in a first position of the pawl housing, the pawl is in registration with the plurality of rack teeth of the rack to prohibit reversal of a direction of movement of the trigger until the pawl is disposed beyond the proximal end or the distal end of the rack and wherein in a second position of the pawl housing, the pawl is out of registration with the plurality of rack teeth of the rack to permit reversal of the direction of movement of the trigger after an initial engagement of the pawl with the rack; a release switch at least partially supported within the housing of the handle assembly and operatively associated with the pawl housing, the release switch selectively actuatable to move the pawl housing from the first position thereof to the second portion thereof, wherein in the second position of the pawl housing, the pawl housing is moved laterally relative to the rack to disengage the pawl from the plurality of rack teeth of the rack, wherein the release switch includes a first end cap and a second end cap, wherein a first side of the housing includes a first switch slot configured to slidably receive the first end cap of the release switch and a second side of the housing includes a second switch slot configured to slidably receive the second end cap of the release switch; a switch pin, wherein the pawl housing defines a central slot therein configured to locate the switch pin, the switch pin slidably extending through the channel of the pawl housing and the pawl to support the pawl within the channel of the pawl housing.
 2. The endoscopic surgical clip applier according to claim 1, wherein the pawl housing defines a channel therein, and wherein the pawl is located within the channel of the pawl housing.
 3. The endoscopic surgical clip applier according to claim 1, wherein the first end cap of the release switch is supported on a first end of the switch pin, on a first side of the pawl housing, and the second end cap of the release switch is supported on a second end of the switch pin, on a second, opposite side of the pawl housing, such that the release switch is accessible via the first and second end caps from the first and second sides of the pawl housing, respectively, to actuate the release switch.
 4. The endoscopic surgical clip applier according to claim 1, wherein the release switch includes: a first biasing member supported on the first end cap and extending between an internal wall of the first switch slot and the first side of the pawl housing; and a second biasing member supported on the second end cap and extending between an internal wall of the second switch slot and the second side of the pawl housing.
 5. The endoscopic surgical clip applier according to claim 4, wherein the first biasing member includes a first biasing force and the second biasing member includes a second biasing force, the first and second biasing forces configured to cooperate to maintain the pawl housing in the first position such that the pawl housing is centered relative to the rack and the pawl is in registration with the plurality of rack teeth.
 6. The endoscopic surgical clip applier according to claim 5, wherein when the release switch is actuated, by actuating the first end cap thereof, the first end cap is moved towards the first side of the pawl housing such that the first end cap engages the pawl housing to move the pawl housing to the second position thereof, towards the second biasing member, and laterally relative to the rack to move the pawl out of registration with the plurality of rack teeth.
 7. The endoscopic surgical clip applier according to claim 5, wherein when the release switch is actuated, by actuating the second end cap thereof, the second end cap is moved towards the second side of the pawl housing such that the second cap engages the pawl housing to move the pawl housing to the second position thereof, towards the first biasing member, and laterally relative to the rack to move the pawl out of registration with the plurality of rack teeth.
 8. The endoscopic surgical clip applier according to claim 7, wherein the rack includes a distal clearance and a proximal clearance configured to receive the pawl in an initial and/or a reset position.
 9. The endoscopic surgical clip applier according to claim 8, wherein the ratchet assembly includes a pawl spring configured to bias the pawl into registration with the rack in the first position, wherein in the second position, the pawl spring and at least one of the first biasing member and the second biasing member are configured to urge the pawl against a side of the rack until the pawl is located within the distal clearance or the proximal clearance of the rack.
 10. The endoscopic surgical clip applier according to claim 9, wherein when the pawl is located within the distal clearance or the proximal clearance of the rack, at least one of the first biasing member and the second biasing member are configured to urge the pawl laterally to the first position thereof, wherein the pawl is centered relative to the rack such that the pawl is in registration with the plurality of rack teeth.
 11. The endoscopic surgical clip applier according to claim 1, wherein the ratchet assembly includes a distal support pin and a proximal support pin, wherein an outer surface of the pawl housing further defines a distal support slot configured for locating the distal support pin and a proximal support slot configured for locating the proximal support pin, the distal support pin and the proximal support pin each coupled to the housing of the handle assembly to slidably mount the pawl housing within the housing of the handle assembly.
 12. The endoscopic surgical clip applier according to claim 1, wherein the endoscopic assembly further comprises a plurality of surgical clips slidably disposed within the shaft assembly and selectively formable between the pair of jaw members, wherein when the pawl housing is in the first position, the pawl is in registration with the rack disposed on the drive bar such that upon actuation of the trigger, the trigger is prevented from reversing the direction of movement thereof until the trigger is fully actuated and a distal most surgical clip of the plurality of surgical clips is fully formed between the pair of jaw members.
 13. The endoscopic surgical clip applier according to claim 12, wherein when the pawl housing is in the second position, the pawl is out of registration with the rack disposed on the drive bar such that upon partial actuation of the trigger, the trigger is capable of reversing the direction of movement thereof such that the distal most surgical clip of the plurality of surgical clips is partially formed between the pair of jaw members.
 14. The endoscopic surgical clip applier according to claim 1, wherein the ratchet assembly includes a cover plate provided on the rack, the cover plate having a pair of wings extending along at least a portion of the rack to prevent lateral movement of the pawl housing and disengagement of the pawl from the plurality of rack teeth during a specific portion of the stroke length of the trigger.
 15. An endoscopic surgical clip applier, comprising: a handle assembly including: a fixed handle; and a trigger pivotally connected to the fixed handle; a shaft assembly extending from the handle assembly; a pair of jaw members operatively coupled to, and extending from the shaft assembly; a drive bar disposed within the handle assembly and operatively coupled to the trigger and the pair of jaw members to move the pair of jaw members between a spaced apart configuration and an approximated configuration upon actuation of the trigger; a ratchet assembly disposed within the handle assembly, the ratchet assembly including: a rack defined on a top portion of the drive bar, the rack including a plurality of rack teeth and having a proximal end and a distal end; a pawl housing movably mounted within the handle assembly, the pawl housing having a pawl being selectively engageable with the plurality of rack teeth of the rack to prohibit, upon actuation of the trigger, a reversal of a direction of movement of the trigger until the pawl is disposed beyond the proximal end or the distal end of the rack after an initial engagement of the pawl with the rack; a release switch at least partially supported within the housing of the handle assembly and operatively associated with the pawl housing, the release switch selectively actuatable to move the pawl housing from the first position thereof to the second portion thereof, wherein in the second position of the pawl housing, the pawl housing is moved laterally relative to the rack to disengage the pawl from the plurality of rack teeth of the rack, wherein the release switch includes a first end cap and a second end cap, wherein a first side of the housing includes a first switch slot configured to slidably receive the first end cap of the release switch and a second side of the housing includes a second switch slot configured to slidably receive the second end cap of the release switch; and a switch pin, wherein the pawl housing defines a central slot therein configured to locate the switch pin, the switch pin slidably extending through the channel of the pawl housing and the pawl to support the pawl within the channel of the pawl housing.
 16. The endoscopic surgical clip applier according to claim 15, further comprising a surgical clip slidably disposed within the shaft assembly and selectively formable between the pair of jaws, wherein when the pawl is in registration with the rack disposed on the drive bar and the trigger is actuated, the trigger is prevented from reversing the direction of movement thereof until the trigger is fully actuated such that the surgical clip is fully formed between the pair of jaw members. 